The present invention relates to a system which connects an image input device such as a digital camera having a plurality of operation modes, and an image processing apparatus such as a personal computer or the like, and inputs and saves images, its control method, and a storage medium.
Conventionally, when an image captured by a digital camera is input to a personal computer, the following procedure is required:
1. The camera is connected to the personal computer via a serial cable.
2. The user starts an application.
3. A TWAIN driver is started from the application.
4. A button or menu command for connecting the camera is pressed.
5. Thumbnails of images in the camera are displayed on the window of the TWAIN driver.
6. The user selects an image to be captured into the personal computer and presses a capture button.
7. The selected image is transferred to the personal computer.
In this manner, in order to capture an image in the digital camera into the personal computer, a given procedure is required, and the user must have certain knowledge. Recently, an RS-232C serial cable is prevalently used as an I/F for connecting a personal computer and camera. This I/F has high compatibility, i.e., is supported by all personal computers, but has low transfer rate. With the use of this I/F, the configuration of image input software such as a TWAIN driver or the like has a fixed procedure for transferring thumbnail data with a small data size first to display image indices in the camera, and then transferring only original images selected by the user.
However, Microsoft Windows98™ formally supports USB (Universal Serial Bus) as a new I/F, and STI (Still Image Captures Architecture and Interfaces) is prepared as a software I/F for digital cameras. USB has a maximum transfer rate of 10 Mbps; an original image can be directly transferred without making the user feel stress as long as it is a compressed file such as a JPEG file or the like. In this manner, an environment for allowing to readily build image input software with a higher degree of freedom without fixing the procedure to that for displaying thumbnails and then transferring only a required original image is in order.
USB can implement hot plugin (a USB device can be plugged or unplugged while a PC is running, and the OS can recognize the plugged or unplugged state), and a mechanism for automatically recognizing the connected camera, and automatically starting a predetermined application associated with the camera by the STI can be provided. As can be seen from the above description, an image can be captured from the camera to the personal computer by the following procedure:
(1) The camera is connected.
(2) The associated application is automatically started. The application automatically starts a corresponding TWAIN driver, which automatically connects the camera and displays thumbnails in the camera.
(3) The user selects an image to be captured and presses a capture button.
(4) The selected image is transferred to the personal computer.
In this manner, steps 2. to 5. in the above procedure can be automated.
The STI has a mechanism for starting corresponding PC software in response to connection of a camera as a trigger. Hence, tedious operation can be greatly reduced, and it is easy even for a novice user of the personal computer to use such system.
However, the STI architecture considers the TWAIN driver as main image input software, and suffers the following shortcomings:
(1) The number of types of applications that can be associated is only one, and the application which runs upon connecting a camera is fixed.
(2) The associated application starts a TWAIN driver corresponding to the camera.
(3) Starting the TWAIN driver means that the application cannot be basically used for purposes other than that for capturing an image into the personal computer.
On the other hand, the digital camera has not only a function of sensing an image, playing back the sensed image on its LCD, and transferring the image to the PC, but also more functions. The number of functions of the digital camera is increasing. For example, the following functions falling outside the range of a function of merely capturing a sensed image into a PC are available:
(1) Slideshow function: All or selected images in the camera are automatically played back on the camera LCD or on a TV via the video output at predetermined time intervals.
(2) On-line image sensing function: An image is previewed on PC software while the PC is connected to the camera. By pressing an image sensing button of that camera or on PC software, the camera senses the previewed image, and automatically transfers the sensed image to the PC. This function become actually usable after USB is supported as a standard I/F. The conventional RS232C can only preview an image for about one frame per sec in a size as small as a thumbnail image, and is not practical.
(3) Divided image synthesis function: In order to sense a panoramic image which cannot be sensed by single image sensing, image sensing is divisionally done a plurality of number of times. These images are automatically stitched by PC synthesis software (to be referred to an stitch synthesis software hereinafter) to form a panoramic image. Upon synthesis, since a common region in neighboring images is detected to automatically recognize the synthesis position, the neighboring images must have common portions. To facilitate such image sensing, the camera has an image sensing mode called a stitch assist mode. At this time, as shown in FIG. 2, a preview image 4b is displayed while displaying a previously sensed image 4a on an LCD, so that the user can easily find the common portion (overlap region). Note that, reference numeral 5 denotes a release switch.
Also, these functions will more often be used in future since they are superior features of digital cameras over film cameras (silver halide cameras).
On the other hand, digital camera users may not always be more or less accustomed with PC operations. That is, users who used film cameras so far may purchase digital cameras as their alternatives. Hence, such users are accustomed with camera operations but are not accustomed with PC operations. Means which allow such users to easily use functions in addition to a function of transferring an image to the personal computer are strongly demanded.